JP2017050734A - Serial communication device, communication system, and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify detection of the terminal of effective data in a receiving device to suppress power consumption.SOLUTION: There is disclosed a serial communication device comprising: an addition part that adds, to the head of data, a start code indicating the head of the data and a length code indicating the length of the data; a transmission part that converts the data to which the start code and length code are added into serial form data and transmits the resulting serial data; a receiving part that receives the data from the transmission part; and a processing part that detects, from the received data, the start code and length code, specifies the position of the head of the data on the basis of the detected start code, specifies the position of the terminal of the data on the basis of the start code and length code, and processes the data on the basis of the specified positions of the head and terminal of the data.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a serial communication device, a communication system, and a communication method.

  There is a technique for performing high-speed serial communication by adding a control code to the beginning and end of image data.

  For example, by adding a plurality of start codes to the beginning of the image data on the transmitting side, adding a plurality of end codes to the end of the image data, performing data transfer, and detecting the start code and the end code on the receiving side Image data is extracted (for example, Patent Document 1).

  However, in the conventional technology, when deserialization is performed, a buffer area for removing both the start code and the end code is provided in the receiving device, so that the circuit scale of the receiving device increases and the power consumption increases. In particular, the termination code becomes redundant in the frame removal process, which causes an increase in circuits operating at high frequencies and an increase in power consumption.

  Therefore, the disclosed technique aims to simplify the detection of the end of valid data on the receiving device side and suppress power consumption.

  In the embodiment, an addition unit for adding a start code indicating the start of data and a length code indicating the length of the data to the start of the data, and data including the start code and the length code are serially A transmitting unit that converts the data into a format and transmits; a receiving unit that receives the data from the transmitting unit; and detects the start code and the length code from the received data, and based on the detected start code A processing unit that identifies the position of the beginning of the data, identifies the position of the end of the data based on the start code and the length code, and processes the data based on the position of the beginning and end of the identified data A serial communication device is disclosed.

  It is possible to simplify the detection of the end of valid data on the receiving device side and to suppress power consumption.

It is a figure which shows the example of a structure of the serial communication apparatus which performs serial transfer. The 1st example of a variable-length code is shown. It is a figure which shows an example of the conversion table for control codes. It is a figure which shows the 1st example of a circuit structure of a deserializer. It is a figure for demonstrating operation | movement of a buffer. It is a figure which shows the 2nd example of the circuit structure of a deserializer. It is a figure which shows the example of the reception processing flow by a deserializer. The 2nd example of a variable-length code is shown. It is a figure which shows the example of a structure of a communication system.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has substantially the same function structure, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(Embodiment 1)
FIG. 1 is a diagram illustrating an example of a serial communication device 1 that performs serial transfer. The serial communication device 1 includes a serializer (SER: Serializer) 20 and a deserializer (DES: Deserializer) 10. In the example of FIG. 1, the serial communication device 1 converts image data into serial data, and transfers the serial data from the serializer 20 to the deserializer 10 via two communication lanes. The serializer 20 includes an encoding unit 22a, an encoding unit 22b, a transmission interface (hereinafter referred to as a TXIF unit) 23, a serial transmission unit 25a, and a serial transmission unit 25b. The serial transmission unit 25a includes a P / S (Parallel / Serial) conversion unit 21a and a driver 5a. The serial transmission unit 25b includes a P / S conversion unit 21b and a driver 5b.

  The deserializer 10 includes a receiver 6a, a receiver 6b, a clock data recovery (hereinafter referred to as a CDR unit (Clock Data Recovery)) 11a, a CDR unit 11b, a decoding unit 12a, a decoding unit 12b, and a receiving interface ( (Hereinafter referred to as RXIF section) 13. The RXIF unit 13 includes a buffer 15a and a buffer 15b.

  As an example to which the serial communication device 1 is applied, for example, a serializer 20 is arranged in a scanner unit of a multifunction image forming apparatus such as an MFP (Multifunction Printer), and a deserializer 10 is arranged in a printing unit. In this case, serial transfer is performed between the scanner unit and the printing unit. The configuration of FIG. 1 can be applied to various apparatuses and systems other than the MFP.

  The TXIF unit 23 is an interface for performing serial transfer. The TXIF unit 23 generates a variable length code by adding a plurality of control codes to the tip of 8-bit parallel data (image data). For example, when the image data includes four color data of black, magenta, cyan, and yellow, the TXIF unit 23 generates a variable length code related to the black and magenta color data. Further, the TXIF unit 23 generates a variable length code relating to cyan and yellow color data. The TXIF unit 23 may further have a skew adjustment function.

  The control code includes a COM code, a length code, and a start code. A plurality of control codes added to the head of the image data are called STP frames. In the first embodiment, it is not necessary to add an END code to the end of the image data.

  FIG. 2 shows a first example of a variable length code. For example, the variable length code α is configured by a combination of the STP frame 31 and the image data 32. In the first embodiment, an END code (end code) may not be added to the end of the image data 32.

  The COM code 33 is stored between the variable length code α and another variable length code adjacent to the variable length code α. The STP frame 31 is composed of a combination of a COM code, a length code (indicated as “Length” in FIG. 3), and an STP code. The COM code is stored at the boundary with other STP codes and length codes. Thus, a distance is provided between the adjacent STP code and length code to facilitate detection of the STP code and length code.

  The length code indicates the data length of data to be transferred (for example, image data 32). The STP code indicates the head position of data to be transferred (for example, image data 32). In addition, although the example in which the number of combinations of the COM code, the length code (Length), and the STP code included in the STP frame 31 is four has been described, the number of combinations may be five or more, and may be three or less. Also good.

  Returning to FIG. The encoding unit 22a converts 8-bit parallel data related to the variable-length code into 10-bit parallel data based on a predetermined conversion table. For example, the encoding unit 22a converts an 8-bit control code (for example, STP code, COM code, etc.) into a 10-bit control code using a conversion table shown in FIG. Is used to convert 8-bit image data into 10-bit image data. Similar to the encoding unit 22a, the encoding unit 22b converts the 8-bit parallel data of the variable length code into the 10-bit parallel data based on a predetermined conversion table.

  In the first embodiment, an example in which 8B / 10B conversion is used will be described. However, the encoding method is not limited to this. Other encoding methods such as 64B / 66B, 64B / 67B, 128B / 130B, TMDS (Transition Minimized Differential Signaling) may be used.

  FIG. 3 is a diagram illustrating an example of a conversion table for control codes. “Symbol Name” indicates the type of symbol code. Twelve types of symbol codes are prepared, and a symbol code is assigned to each of one type of COM code, five types of STP codes (STP1 to 5), and five types of END codes (END1 to 5). The STP code corresponds to the start code, and the END code corresponds to the end code. The COM code is a code stored at the boundary between image data. By assigning “K28.5” in which a 0 or 1 bit is continued five times to the COM code, it is easy to detect a boundary with another adjacent variable length code. “Data Byte Name” indicates the name of the symbol code. “Data Byte Value (hex)” represents an 8-bit symbol code in hexadecimal. “8B code” indicates an 8-bit symbol code. The “10B code” is a 10-bit symbol code of polarity RD + (running disparity) and polarity RD− corresponding to the 8-bit symbol code. The encoding units 22a and 22b assign a 10-bit symbol code of polarity RD + or polarity RD− to the 8-bit symbol code based on a predetermined rule. The polarity RD− is a symbol code obtained by bit-inverting the bit string of the polarity RD +.

  For example, the encoding unit 22a alternately assigns symbol codes of polarity RD + or polarity RD−, thereby avoiding that 0 or 1 bits continue for a predetermined number of times (for example, 5 times) and stabilizes serial communication. Note that the encoding unit 22a may not assign a symbol code such as STP5 in which one or more 0 or 1 bits are consecutive in one symbol code.

  In addition, the encoding unit 22b alternately assigns symbol codes of polarity RD + or polarity RD− similarly to the encoding unit 22a. Also for image data (D code), symbol codes having positive and negative polarities may be alternately assigned in the same manner as control codes (K codes) such as STP codes and COM codes.

  Returning to FIG. The P / S conversion unit 21a divides each 10-bit parallel data related to the variable-length code α into 1-bit data and converts it into 10-bit serial data. For example, when the image data includes four color data of black, magenta, cyan, and yellow, the P / S converter 21a divides the 10-bit parallel data of each of black and magenta into 1 bit. Convert to bit serial data. Further, the P / S conversion unit 21b divides cyan and yellow 10-bit parallel data into 1-bit data and converts them into 10-bit serial data. Note that the P / S converters 21a and 21b may perform an emphasis process on the serial data.

  Subsequently, the P / S converter 21a transfers serial data from the driver 5a to the deserializer 10 via Lane0. The P / S converter 21b transfers serial data from the driver 5b to the deserializer 10 via Lane1.

  Note that the driver 5a transmits serial data and data having an opposite phase obtained by inverting the phase of the serial data using Lane0. The driver 5b also transmits serial data using the same transmission method. The P / S conversion unit 21a and the driver 5a may be combined and used as the serial transmission unit 25a. Further, the P / S conversion unit 21b and the driver 5b may be combined and used as the serial transmission unit 25b.

  In the deserializer 10, the CDR unit 11a reproduces serial data based on the differential signal received by the receiver 6a via Lane0, extracts the clock signal embedded in the serial data, and separates the clock data from the serial data.

  The CDR unit 11b supplies the extracted clock signal and transmission data to the decoding unit 12 in the same manner as the CDR unit 11a.

  The decoding unit 12a converts serial data into parallel data. Subsequently, the decoding unit 12a converts the 10-bit parallel data related to the variable-length code α into 8-bit parallel data based on a predetermined conversion table. The decoding unit 12a may convert 10-bit parallel data related to the variable-length code α into 8-bit parallel data based on the conversion table of FIG. Subsequently, the decoding unit 12a outputs the decoded 8-bit parallel data (variable length code α) to the buffer 15a.

  The decoding unit 12b processes serial data in the same manner as the decoding unit 12a, and outputs 8-bit parallel data to the buffer 15b.

  The RXIF unit 13 includes buffers 15a and 15b. The RXIF unit 13 detects the STP code stored in the STP frame 31, and specifies the start position of the image data based on the STP code. Further, the RXIF unit 13 further detects the length code, and specifies the position of the end of the image data based on the STP code and the detected length code. For example, the RXIF unit 13 calculates the end address of the image data by adding the data length of the image data indicated by the length code to the head address of the image data specified by the STP code. Subsequently, the RXIF unit 13 performs a frame removal process for removing the STP frame from the variable length code α. Subsequently, the RXIF unit 13 outputs the image data to the buffers 15a and 15b.

  The RXIF unit 13 detects the beginning and end of the image data on condition that a predetermined number or more of STP codes and length codes are detected. Alternatively, the head and end of the image data may be detected on condition that all STP codes and length codes have been detected.

  The RXIF unit 13 starts read processing of the buffers 15a and 15b when the end of the detected image data is output to the buffer 15a or 15b. The RXIF unit 13 transmits the image data stored in the buffers 15a and 15b to a subsequent image processing unit (not shown) in a synchronized state in units of clocks.

  The RXIF unit 13 sets a read pointer (rptr) at the head position of the image data and sets a write pointer (wptr) at the end position of the image data. The RXIF unit 13 obtains the buffer storage size by calculating the difference between the rptr address and the wptr address. The RXIF unit 13 may start read processing of the buffer 15a or 15b first, even before the end of the image data is output to the buffer 15a or 15b, when the buffer storage size becomes a predetermined value or more. .

  The RXIF unit 13 performs deskew adjustment when there is a delay between Lane0 and Lane1. Further, the RXIF unit 13 corrects the frequency deviation when a frequency deviation occurs between Lane 0 and Lane 1.

  FIG. 4 is a diagram illustrating a first example of the circuit configuration of the deserializer 10. The deserializer 10 includes a CDR unit 11a, a CDR unit 11b, a decoding unit 12a, a decoding unit 12b, an RXIF unit 13, a skew value measurement circuit 14, a buffer 15a, a buffer 15b, and a register 16.

  The CDR unit 11a extracts a clock and transmission data from the serial data received by the receiver 6a, and supplies the serial data to the decoding unit 12a. The CDR unit 11b performs the same processing as the CDR unit 11a, and transmits serial data to the decoding unit 12a.

  Each decoding unit 12 converts serial data into parallel data. Further, the decoding unit 12a performs a frequency lock detection process for detecting the lock state of the signal frequency used in the deserializer 10, a symbol boundary detection process for detecting the boundary between each control code and each data code, and the like. Subsequently, the decoding unit 12 a converts 10-bit parallel data into 8-bit parallel data based on the conversion table of FIG. 2 and the like, and outputs the converted data to the RXIF unit 13.

  The RXIF unit 13 identifies the end of the image data based on the start code and length code included in the STP frame. Subsequently, the RXIF unit 13 removes the STP frame from the variable length code α to obtain image data, and then accumulates the image data in the buffers 15a and 15b.

  The RXIF unit 13 starts the read process when the buffer storage size of the buffer 15a or 15b becomes equal to or larger than a predetermined value. Further, the RXIF unit 13 starts the read process when detecting the end of the image data. In addition, since a delay occurs between Lane 0 and Lane 1, read processing is started when deskew is required. The read processing timing will be described later. The buffer storage sizes of the buffers 15a and 15b are measured by the skew value measurement circuit 14.

  Subsequently, the RXIF unit 13 transmits the image data read from the buffers 15a and 15b to the subsequent image processing unit.

  FIG. 5 is a diagram for explaining the operation of the buffer 15. The upper row shows the buffer 15a, and the lower row shows the buffer 15b. The squares in the buffer 15a and the buffer 15b indicate the number of buffer stages. The buffer stage number is obtained by dividing the storage capacity of the buffer for each predetermined capacity. When image data is written to the buffer 15a and the buffer 15b, the image data is stored in order from the right square. For example, the image data transmitted via Lane 1 is written to the buffer 15b, so that the image data is stored in the number of buffer stages from # 0 to # 4.

  Rptr is set at the right end of the buffer 15b, and wptr is set at the end of # 4. The RXIF unit 13 obtains the buffer storage size by calculating a difference value between the address of rptr and the address of wptr. The RXIF unit 13 starts the read process when the buffer storage size is equal to or larger than the predetermined value.

  Further, when the RXIF unit 13 detects the output of the end of the image data to the buffers 15a and 15b, it starts the read process. Specifically, the RXIF unit 13 sets the number of buffer stages when the end of the image data is stored based on the length code included in the variable length code α, and the image data is stored up to the set number of stages. By detecting this, it may be detected that the end of the image data has been output to the buffers 15a and 15b.

  For example, the RXIF unit 13 uses the length code included in the variable length code α to calculate the buffer stage number “5” when the end of the image data is stored. Subsequently, the RXIF unit 13 detects that the end of the image data is output to the buffers 15a and 15b by storing the image data up to # 5.

  Note that the RXIF unit 13 may start the read process even when the end of the image data is detected, when the buffer storage size is equal to or larger than the predetermined value. In such a case, the RXIF unit 13 performs the write process in parallel with the read process until the end of the image data is detected.

  Further, in the case where a time delay occurs between the buffer 15a and the buffer 15b, the RXIF unit 13 may start the read process by the other buffer in accordance with the buffer from which the read process has been started. For example, when # 5 of the buffer 15a is the end of the image data, the RXIF unit 13 starts the read process of the buffer 15a. Further, even before the end of the image data is detected by the buffer 15b, the RXIF unit 13 may start the read process of the buffer 15b with the same clock as the clock at which the read process of the buffer 15a is started. . Thereby, the RXIF unit 13 can synchronize the image data of the buffer 15a and the buffer 15b in units of clocks. In the buffer 15b, the write process is executed in parallel with the read process.

  FIG. 6 is a diagram illustrating a second example of the circuit configuration of the deserializer 10. The deserializer 10 includes a CDR unit 11a, a CDR unit 11b, a decoding unit 12a, a decoding unit 12b, a descrambling processing unit 17a, a descrambling processing unit 17b, an interleaving processing unit 18a, an interleaving processing unit 18b, It has an RSDec processing unit 19a, an RSDec processing unit 19b, an RXIF unit 13, and a register 16. The RXIF unit 13 includes a buffer 15a and a buffer 15b.

  The CDR unit 11a extracts a clock and transmission data from the serial data received by the receiver 6a, and supplies the serial data to the decoding unit 12a. Subsequently, the decoding unit 12a converts serial data into parallel data. Subsequently, the descramble processing unit 17a releases (descrambles) the scrambled data by a scrambler (not shown) of the serializer 20. Subsequently, the interleave processing unit 18a restores the data that has been output after the data order is rearranged by the serializer 20 in order to prevent a burst error. Subsequently, the RSDec processing unit 19a performs error correction using the error correction code added to the variable length code α, and then deletes the error correction code. Subsequently, the RSDec processing unit 19 a outputs the variable length code to the RXIF unit 13.

  The CDR unit 11b, the decoding unit 12b, the descrambling processing unit 17b, the interleaving processing unit 18b, and the RSDec processing unit 19b also execute the same processing as described above.

  When the deserializer 10 has the configuration shown in FIG. 6, the serializer 20 includes a scramble processing unit (not shown) and an interleave processing unit.

  FIG. 7 is a diagram illustrating an example of a flow of reception processing by the deserializer 10. The deserializer 10 converts the received serial data into parallel data, and converts 10-bit parallel data into 8-bit parallel data based on a predetermined conversion table (step S10). Subsequently, the deserializer 10 detects the STP code and the length code for each Lane (Step S11). Thereby, the deserializer 10 detects the head and the end of the image data. Note that the deserializer 10 may detect the head and the end of the image data on condition that the STP code and the length code included in the STP frame are detected a predetermined number of times or more. Further, the deserializer 10 may detect the head and the end of the image data on condition that all STP codes and length codes are detected.

  The deserializer 10 removes the STP frame from the variable length code α for each Lane, and then transfers the image data to the buffers 15a and 15b (Step S12).

  Subsequently, the deserializer 10 determines whether or not the amount of image data stored in the buffers 15a and 15b is equal to or greater than a specified amount (step S13). When the buffer storage size in the buffers 15a and 15b is equal to or larger than the specified amount (step S13 Yes), the deserializer 10 proceeds to the process of step S16. On the other hand, when the buffer storage size in the buffers 15a and 15b is less than the specified amount (No in step S13), the deserializer 10 proceeds to the process in step S14. The buffer storage size is calculated from the difference between the address of the pointer rptr indicating the head of the image data and the address of the pointer wptr indicating the end.

  In step S14, when the deserializer 10 detects the end of the data (step S14 Yes), the process proceeds to step S16. On the other hand, when the deserializer 10 has not detected the end of the data (No in step S14), the deserializer 10 continues the write process to the buffers 15a and 15b (step S15), and returns to step S13.

  In step S14, the deserializer 10 compares the number of buffer stages of the written image data with the end_ptr value that is the number of buffer stages corresponding to the end of the image data. The deserializer 10 determines that the end of the data has been detected when the number of buffer stages of the written image data is equal to the end_ptr value.

  The method for detecting the end of the data is an example. For example, the deserializer 10 determines the data based on the comparison between the address of the end position of the image data written to the buffers 15a and 15b and the address of the position obtained by adding the data length of the image data to the address of the position where writing is started. The end may be detected.

  In step S16, the deserializer 10 starts read processing from the buffers 15a and 15b (step S16). Subsequently, the deserializer 10 determines whether or not the write processing to the buffers 15a and 15b has been completed (step S17). When the write process is completed (Yes at Step S17), the deserializer 10 proceeds to the process at Step S19. On the other hand, when the write process is not completed (No at Step S17), the deserializer 10 performs the write process on the buffers 15a and 15b until the end of the data is detected (Step S18), and returns to Step S16.

  The deserializer 10 determines that the write processing has been performed up to the end of the data when the number of buffer stages of the written image data is equal to the end_ptr value.

  In step S19, the deserializer 10 holds, as an end_ptr value, the number of buffer stages from which the data end has been detected based on the STP code and the length code in order to manage the number of stages until the data end is detected (step S19).

  Note that the deserializer 10 may detect the end of the data using the end_ptr value held in step S19 in step S14 and step S18. For example, in step S18, when the number of buffer stages corresponding to the data end is 5, the deserializer 10 sets the end_ptr value to 5. In step S <b> 18, the deserializer 10 performs a write process until the number of buffer stages of the written image data ≧ 5.

  The deserializer 10 transfers the read image data to the image processing unit until the read processing from the buffers 15a and 15b is completed (step S21). Subsequently, when the deserializer 10 completes the transfer of the image data to the image processing unit (step S21), the deserializer 10 ends the process.

  The deserializer 10 executes the processes of steps S10 to S21 until the transfer of all the image data is completed.

  The write process performed in step S15 and the write process performed in step S18 will be described with specific examples.

  For example, the deserializer 10 continues the write process in step S15 until the end of the data is detected in the buffer 15a or 15b.

  When the deserializer 10 detects the end of the data in the buffer 15a, the deserializer 10 starts the read process of the buffer 15a (step S16) and starts the read process of the buffer 15b (step S16).

  Since the deserializer 10 has completed the write process of the buffer 15a, the deserializer 10 proceeds to the process of step S19 for the buffer 15a. On the other hand, since the write processing of the buffer 15b is not completed, the deserializer 10 performs the write processing of step S18 while performing the read processing of step S16. The deserializer 10 executes the write process in step S18 for the buffer 15b until the end of the data is detected.

  As described above, since the capacity of the buffer used when removing the control code can be reduced as described in the first embodiment, power consumption in the deserializer 10 can be suppressed.

(Embodiment 2)
The deserializer 10 may specify the position of the end of the image data based on a variable length code having an END code at the end of the image data. The END code is a control code (K code) indicating the end of valid data.

  In this case, the END code is used for assisting data end detection by the method of Embodiment 1 or for improving accuracy. Note that the configuration of the serial communication device 1 is the same as that of the first embodiment, and thus the description thereof is omitted.

  FIG. 8 shows a second example of the variable length code. The variable length code α is configured by a combination of an STP frame 41, image data 42, and an END code 44. The COM code 43 is stored between the variable length codes α.

  The STP frame 41 includes a combination of a COM code, a length code (indicated as “Length” in FIG. 8), and an STP code. The COM code is stored at the boundary with other STP codes and length codes. The length code indicates the data length of the image data 42. The STP code indicates the start position of the image data 42. In addition, although the example in which the number of combinations of the COM code, the length code, and the STP code included in the STP frame 41 is four has been described, the number of combinations may be 5 or more, or 3 or less.

  Each STP code indicates the position of the tip of the image data 42, and the RXIF unit 13 of the deserializer 10 adds the data length indicated by the length data to the position of the tip, thereby determining the position of the end of the image data. Can be acquired. The RXIF unit 13 determines whether or not the END code 44 exists at the end position of the image data. The RXIF unit 13 specifies the position of the end of the image data 42 on condition that the end position of the image data has the END code 44.

  Note that the RXIF unit 13 may specify the position of the end of the image data 42 on the condition that all of the detected length codes have the same value.

  Thus, by detecting the end of the image data on condition that the END code is detected at the end position of the image data, the reliability of detection of the end of the image data can be improved.

  In addition, only one END code may be added to the end of the image data, and the data length of the variable length code α can be shortened, so that the capacity of the buffer used when removing the control code is reduced. Power consumption can be reduced.

  The serializer 20 may add a cyclic code, an error correction code, and the like before and after the END code, and the deserializer 10 may detect and process the added cyclic code, error correction code, and the like.

  The serial communication device has been described above by way of the embodiment. However, the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the present invention.

  The serial transfer described in the first and second embodiments can be applied to a communication system including a plurality of devices. An example in which the serial transfer described in the first and second embodiments is applied to a communication system will be described.

  FIG. 9 is a diagram illustrating an example of the configuration of the communication system 2. The communication system 2 includes a printer server 3 and a scanner 4. The printer server 3 includes a deserializer 10. The scanner 4 includes a serializer 20. As described above, the serial transfer described in the first and second embodiments may be applied to communication between apparatuses.

  In the first embodiment, two serial transfer paths and two buffers are used. However, the present invention is not limited to this. One path and buffer may be used, and four links, eight links, and the like may be used. .

  In the first embodiment, a cyclic code and an error correction code may be added behind the image data.

  In the present embodiment, the buffer 15 is an example of a storage area. The RXIF unit 13 is an example of a processing unit. The TXIF unit 23 is an example of an adding unit. The serial transmission unit 25 is an example of a transmission unit. Image data is an example of received data. The STP code is an example of a start code. The END code is an example of a termination code.

DESCRIPTION OF SYMBOLS 1 Serial communication apparatus 2 Communication system 6a, 6b Receiver (reception part)
10 Deserializer 11a, 11b CDR unit 12a, 12b Decoding unit 13 RXIF unit (processing unit)
15a, 15b Buffer 20 Serializers 21a, 21b P / S conversion units 22a, 22b Encoding unit 23 TXIF unit (addition unit)
25 Serial transmitter

JP 2010-114762 A

Claims (8)

An adding unit for adding a start code indicating the head of data and a length code indicating the length of the data to the head of the data;
A transmission unit that converts the data added with the start code and the length code into a serial format and transmits the data;
A receiver that receives the data from the transmitter;
The start code and the length code are detected from the received data, a head position of the data is specified based on the detected start code, and the start of the data is determined based on the start code and the length code. A serial communication apparatus comprising: a processing unit that specifies a terminal position and processes data based on the head and terminal positions of the specified data.   2. The processing unit according to claim 1, wherein the processing unit accumulates the received data in a storage area in order from the identified tip position, and reads the data stored in the storage area from the tip position to the end position. Serial communication device. The adding unit adds a plurality of the start codes and a plurality of the length codes to the data,
The serial communication device according to claim 1, wherein the processing unit identifies the position of the terminal when detecting a plurality of the length codes and a start code corresponding to the length codes.   The serial communication device according to claim 1, wherein the processing unit specifies the position of the end when the length code having the same value of 2 or more is detected. The adding unit adds at least one end code to the end of the data;
The serial communication device according to claim 3, wherein the processing unit specifies the position of the terminal when the terminal code is detected.   The processing unit starts reading data when it is accumulated in a storage area up to the end position of the specified data or when a predetermined amount or more of data is stored in the storage area. The serial communication device according to any one of the above. In a communication system in which a receiving device receives data converted into a serial format by a transmitting device,
The transmitter is
An adding unit for adding a start code indicating the head of the data and a length code indicating the length of the data to the head of the data;
A transmission unit that converts the data into a serial format and transmits the data to the receiving device;
The receiving device is:
A receiver for receiving the data from the transmitter;
The received data is converted into a parallel format and then stored in a storage area, and a start code indicating the head of the data and a length code indicating the length of the data added to the head of the data are detected. The start position of the data is specified based on the detected start code, the end position of the data is specified based on the start code and the length code, and the start and end positions of the specified data are specified. A processing unit for processing data based on
A communication system. Adding a start code indicating the beginning of data and a length code indicating the length of the data to the beginning of the data;
The data with the start code and the length code added is converted into a serial format and transmitted,
Receiving the transmitted data;
The received data is converted into a parallel format and then stored in a storage area,
Detecting a start code indicating the head of the data and a length code indicating the length of the data, which is added to the head of the data;
Identifying the start position of the data based on the detected start code;
Locating the end of the data based on the start code and the length code;
A communication method in which a serial communication apparatus executes a process of extracting data based on the start and end positions of the specified data.

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